Airport month record

PDXMAY

Portland International in May 2026

Departures: 5,535
Month: May 2026
National, same month: 78.6%
Carriers: 7

Historical statistics for May 2026, not live status or a forecast for this year’s May. For today’s conditions at PDX, see live FAA status.

PDX in May lands a B+, 5 points better than the national rate of 78.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 5,535 flights, of which Delta Air Lines flew 610 at 89.8% on time.

Delta Air Lines is the most reliable of the six carriers covered here at 89.8% on time across 610 flights.

On time

83.9%

Arrivals under 15 minutes late, of 5,501 completed departures

Avg delay

62 min

Across delayed arrivals only, not all flights

Cancelled

0.42%

Nationally in May: 0.92%

Whole year

82.6%

PDX across all twelve months

These figures cover 5,535 departures from Portland International in May 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

May next to PDX's other months

Against PDX's own year, May ran about a point better than the twelve-month rate of 82.6%, which makes it number six of twelve months, best first. Cancellations were unusually low for PDX in May, at 0.42% against 0.77% across the year. Either side of it, April ran 86.1% on time and June 80.3%, so this month sits in line with its neighbours.

PDX month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	5,864	75.7%	65 min	1.18%	B
August 2025	5,685	80.9%	60 min	0.67%	B+
September 2025	5,269	83.7%	51 min	0.17%	B+
October 2025	5,493	82.1%	53 min	0.64%	B+
November 2025	4,976	84.2%	59 min	1.51%	B
December 2025	5,124	79.3%	59 min	0.60%	B+
January 2026	4,537	85.6%	66 min	1.41%	A
February 2026	4,182	86.3%	56 min	0.69%	A+
March 2026	5,113	86.3%	69 min	0.94%	A+
April 2026	5,040	86.1%	63 min	0.48%	A+
May 2026 (this page)	5,535	83.9%	62 min	0.42%	B+
June 2026	6,024	80.3%	65 min	0.61%	B+

Departure window

The best time of day to leave PDX in May

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against 15 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,345 flights90.5%
8am–11am1,002 flights86.6%
11am–2pm777 flights80.2%
2pm–5pm834 flights79.2%
5pm–8pm832 flights78.1%
8pm–5am745 flights83.7%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 90.5% of the time, against 78.1% for the evening window. That is 12 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 1,345 flights scheduled in it.

Across the week, Saturday is the strongest day at 88.1% on time and Thursday the weakest at 79.4%. 9 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at PDX in May

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 89.8% of the time; Southwest Airlines manages 75.3%. Sample sizes sit next to every figure, because a two-point gap across 686 flights means less than a ten-point one.

Carriers at PDX in May 2026
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlines	2,071	86.2%	45 min	0.19%	A+
SkyWest Airlines	1,020	87.3%	58 min	0.29%	A+
Southwest Airlines	686	75.3%	46 min	0.15%	B+
United Airlines	617	78.7%	63 min	0.32%	B+
Delta Air Lines	610	89.8%	131 min	0.82%	A+
American Airlines	429	78.3%	92 min	1.63%	B
Frontier Airlinesthin sample	61	93.3%	65 min	1.64%	A

The spread between Delta and Southwest is 15 points, wide enough that it should decide the booking. On a hundred trips that is 15 more arrivals inside the on-time window.

Route by route

Busiest routes out of PDX in May

Routes from PDX in May 2026
Route	Flights	On time	Avg delay	Cancelled	Grade
PDX to SEA · Seattle	391	85.9%	42 min	0.26%	A+
PDX to LAX · Los Angeles	377	89.6%	82 min	0.27%	A+
PDX to DEN · Denver	367	83.7%	46 min	0.00%	B+
PDX to PHX · Phoenixthin sample	314	83.4%	79 min	0.00%	B+
PDX to SFO · San Franciscothin sample	299	47.7%	62 min	0.33%	F+
PDX to ORD · Chicagothin sample	285	84.2%	64 min	0.00%	B+
PDX to LAS · Las Vegasthin sample	237	85.1%	45 min	0.42%	A+
PDX to DFW · Dallas-Fort Worththin sample	203	80.1%	99 min	3.45%	B−
PDX to SLC · Salt Lake Citythin sample	192	92.1%	106 min	1.04%	A
PDX to SMF · Sacramentothin sample	166	82.5%	60 min	0.00%	B+
PDX to SAN · San Diegothin sample	155	83.9%	38 min	0.00%	B+
PDX to MSP · Minneapolisthin sample	142	95.1%	56 min	0.00%	A+
PDX to ATL · Atlantathin sample	129	87.6%	86 min	0.00%	A+
PDX to SNA · Santa Anathin sample	124	98.4%	19 min	0.81%	A+
PDX to IAH · Houstonthin sample	119	85.7%	56 min	0.00%	A+
PDX to SJC · San Josethin sample	116	83.6%	58 min	0.00%	B+
PDX to ANC · Anchoragethin sample	112	88.3%	45 min	0.00%	A+
PDX to OAK · Oaklandthin sample	111	79.3%	41 min	0.00%	B+
PDX to BUR · Burbankthin sample	91	90.0%	37 min	1.10%	A
PDX to JFK · New Yorkthin sample	87	91.8%	188 min	1.15%	A
PDX to HNL · Honoluluthin sample	79	64.1%	33 min	1.27%	D
PDX to BOI · Boisethin sample	76	84.0%	41 min	1.32%	B
PDX to EUG · Eugenethin sample	74	89.2%	49 min	0.00%	A+
PDX to EWR · Newarkthin sample	71	94.3%	45 min	1.41%	A
PDX to STS · Santa Rosathin sample	70	92.9%	108 min	0.00%	A+

Delay causes

What held PDX up in May

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 55,000 reported delay minutes.

Carrier
38%
Late-arriving aircraft
35%
National Airspace System
25%
Extreme weather
2%
Security
0%

35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 55,000 reported delay minutes here, that single category outweighs weather by 21 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 55,208 reported delay minutes.

Cancellations are rare at 0.42%, below the national 0.92% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Badly late arrivals are rare here: only 4.0% land an hour or more behind schedule, against 7.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

What to do with this

Flying from PDX in May

For a May trip through PDX: expect 83.9% on time and 0.42% cancelled, going by May 2026. The 5am–8am window was the strongest part of the day.

Portland International (PDX), the whole year
PDX in July75.7%
PDX in August80.9%
PDX in September83.7%
PDX in October82.1%
PDX in November84.2%
PDX in December79.3%
PDX in January85.6%
PDX in February86.3%
PDX in March86.3%
PDX in April86.1%
PDX in June80.3%

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures